▎ 摘　　要

NOVELTY - Preparing water soluble graphene comprises e.g. (i) selecting two graphite rods made of natural graphite as electrode, taking aqueous solution of ammonium sulfate as electrolyte, electrolytically stripping graphite rods to obtain electrolytic graphene, (ii) placing electrolytic graphene in three-necked round bottom flask, placing aqueous solution in serpentine condensate tube at 0-6 degrees C, pouring concentrated nitric acid into three-necked flask, (iii) immersing three-necked round bottom flask of step (ii) in oil bath, passing argon or nitrogen gas into flask, and (iv) evaporating nitric acid. USE - The method is useful for preparing water soluble graphene. ADVANTAGE - The graphene has low cost and simple preparation method. DETAILED DESCRIPTION - Preparing water soluble graphene comprises (i) selecting two graphite rods made of natural graphite as electrode, terminal connected to positive pole of DC power supply, one end connected to the cathode electrode, taking aqueous solution of ammonium sulfate having concentration of 1-5 mg/ml as electrolyte in electrolytic cell, and electrolytically stripping graphite rods at 8-12 V and 0.5-3 A to obtain electrolytic graphene, (ii) placing 100 g electrolytic graphene obtained in step (i) in three-necked round bottom flask, one end of both sides of the three-necked flask is connected with argon or nitrogen gas bottle, and one end is connected to the tail gas treatment device of sodium hydroxide solution, neck of three-necked flask is connected to serpentine condensation tube, placing aqueous solution in serpentine condensate tube at 0-6 degrees C, pouring 300-400 ml of 68 wt.% concentrated nitric acid into three-necked flask, and stirring, (iii) immersing three-necked round bottom flask of step (ii) in oil bath, setting temperature of oil bath to 180-200 degrees C for 18-24 hours, and passing argon or nitrogen gas at a flow rate of 2-10 sccm into flask to take away some of decomposed product of nitric acid, and (iv) evaporating nitric acid in step (iii), and then remaining product in three-necked flask is water-soluble graphene.